He became known by the aliases Guacho and William Quiñónez.ArÃzala led FARC's 29th Front.
He participated in the peace process between FARC and the Colombian government, but broke away in 2017, choosing not to acknowledge a ceasefire brokered in June 2016.
Subsequently, the 29th Front was renamed the Oliver Sinisterra Front.
ArÃzala's faction was based in Nariño Department, where it often engaged with the United Guerrillas of the Pacific, led by another FARC dissident.
Under his leadership, the Oliver Sinisterra Front captured and killed two journalists and their driver in April 2018, and separately held an Ecuadorian man and woman.
The governments of Colombia and Ecuador both offered rewards of $100,000 for information resulting in Arizala's capture.ArÃzala died at the age of 29 on 21 December 2018 in a joint military and police operation launched by Colombia and Ecuador near Tumaco, Colombia.